1. Field of the Invention
My invention relates to mechanical-power transmissions which vary the ratio of their output-torque to their input-torque, and in particular, my invention relates to those examples of said transmissions which comprise gears, or equivalents thereof, and which vary the said ratio automatically.
2. Description of the Prior Art
The only fully successful automatic ratio-varying geared transmission is the automobile automatic transmission, introduced half a century ago, wherein a particular gear-ratio is selected, from among a plurality of different gear-ratios provided, to engage the power input to the transmission output by means of an automatic control system comprising sensors, actuators and clutches responsive to the varying automobile operating conditions. The said automobile automatic transmission is preferably coupled to the engine output with a hydraulic torque-converter for cushioning the shock of torque transition as gears are shifted. Many attempts have been made in the prior art to devise an automatic, self-adjusting stepless ratio-varying geared transmission without a control system, but none has proven successful.